Devices And Methods For Preparation Of Vertebral Members

ABSTRACT

Devices and methods for preparing a surgical site, and in particular vertebral members, which may include a retractable tool and an actuator. The tool may include distal and proximal members. A distal side of the distal member may be fixed in a longitudinal direction and pivotable at a point of rotation. A proximal side of the proximal member may be pivotably connected to the actuator. In a retracted position, the distal member may be pivotably connected to the proximal member longitudinally in between the point of rotation and the proximal side of the proximal member. Moving the actuator in a distal direction may push the proximal member and the distal member such that the proximal member pivots with respect to the actuator and distal member, the distal member pivots with respect to the proximal member and point of rotation, and the proximal member and distal member move laterally outward.

This application claims the benefit of U.S. Provisional PatentApplication No. 61/919,994, filed Dec. 23, 2013, which is hereinincorporated by reference in its entirety.

BACKGROUND

1. Field

The present embodiments relate to devices and methods for preparingsurgical sites, and in particular, vertebral members, and moreparticularly, to devices and methods for preparing an intervertebralspace between two adjacent vertebral bodies of two vertebrae of a spinalcolumn, including, for example, sizing, surface preparation, anddistraction.

2. Background

There remains a need for devices and methods for preparing a surgicalsite, and in particular, for preparing an intervertebral space forreceiving an implant, such as a vertebral fusion implant.

SUMMARY

Embodiments provide devices and methods for preparing surgical sites,and in particular, vertebral members. Vertebral members may include, forexample, any structures or corresponding spaces associated with a spine,including without limitation vertebrae, disc annuluses, disc nucleuses,cartilage, endplates, and ligaments.

In one aspect, a device for preparation of a surgical site may include aretractable tool and an actuator connected to the retractable tool. Theretractable tool may include a distal member and a proximal member. Adistal side of the distal member may be fixed in a longitudinaldirection and pivotable at a point of rotation. A proximal side of theproximal member may be pivotably connected to the actuator. In aretracted position, the distal member may be pivotably connected to theproximal member longitudinally in between the point of rotation and theproximal side of the proximal member. Moving the actuator in a distaldirection may push the proximal member and the distal member such thatthe proximal member pivots with respect to the actuator and the distalmember, the distal member pivots with respect to the proximal member andthe point of rotation, and the proximal member and the distal membermove laterally outward with respect to the longitudinal direction.

In another aspect, the actuator may include an actuator rod and anactuator handle. A distal end of the actuator rod may be connected tothe proximal end of the proximal member. A proximal end of the actuatorrod may be connected to the actuator handle.

In another aspect, the actuator rod may be connected to the proximalmember of the retractable tool by a threaded connection. Rotation of theactuator rod may adjust the distance between the actuator handle and theproximal member.

In another aspect, the device may further include a cannula. Theactuator rod may be disposed within the cannula. The cannula may definean opening at a tip portion of the device. The proximal member and thedistal member may be disposed within the opening when in the retractedposition. The distal end of the distal member may be pivotably connectedto the cannula at a distal end of the opening. The proximal member andthe distal member may extend out of the opening when the actuator rodmoves in the distal direction.

In another aspect, in the retracted position, an outer surface of theproximal member, an outer surface of the distal member, and an outersurface of the cannula around the opening may be generally flush witheach other.

In another aspect, the device may further include a locking mechanismthat prevents movement of the actuator rod in the longitudinal directionbut allows rotational movement of the actuator rod.

In another aspect, the locking mechanism may include at least one ofannular ribs and annular grooves on the actuator rod, and a buttonhaving at least one of annular ribs and annular grooves that engage anddisengage the at least one of annular ribs and annular grooves of theactuator rod.

In another aspect, the device may further include a fixed handle on aproximal side of the cannula. Travel of the actuator handle in a distaldirection may be limited by contacting the fixed handle.

In another aspect, at least one of the proximal member, the distalmember, and the cannula may have surface structures for modifying asurface of a vertebral member.

In another aspect, the device may further include a depth gaugeassembly.

In another aspect, the device may be used for sizing, surfacepreparation, or distraction.

In another aspect, a proximal end of the distal member may be pivotablyconnected to a distal end of the proximal member.

In another aspect, a distal end of the proximal member may be pivotablyconnected to an intermediate portion of the distal member. In theretracted position, an extension portion of the distal member may extendbeyond the distal end of the proximal member toward the proximal end ofthe proximal member, and overlap the proximal member.

In another aspect, the proximal member may define a recessed portion forreceiving the extension portion of the distal member so that an outersurface of the distal member and an outer surface of the proximal memberare substantially flush when in the retracted position.

In another aspect, a proximal end of the distal member may be pivotablyconnected to an intermediate portion of the proximal member. In theretracted position, an extension portion of the proximal member mayextend beyond the proximal end of the distal member toward the distalend of the distal member, and overlap the distal member.

In another aspect, the distal member may define a recessed portion forreceiving the extension portion of the proximal member so that an outersurface of the proximal member and an outer surface of the distal memberare substantially flush when in the retracted position.

In another aspect, at least one of the proximal member and the distalmember may be shaped to match a shape of an implantation site.

Another aspect provides a device for preparing a surgical site. Thedevice may extend from a proximal handle portion to a distal tipportion, and may define a longitudinal axis. The device may include acannula, a cannula handle, an actuator rod, an actuator handle, a distalmember, and a proximal member. The cannula may extend generally alongthe longitudinal axis and define an opening at a distal portion of thecannula. The cannula handle may be fixed to a proximal portion of thecannula. The actuator rod may be disposed within the cannula andmoveable within the cannula in a longitudinal direction generally alongthe longitudinal axis. The actuator handle may be attached to a proximalportion of the actuator rod and may be disposed proximal to the cannulahandle. A distal side of the distal member may be pivotably connected ata first point to a distal portion of the cannula. A proximal side of theproximal member may be pivotably connected to the actuator rod at asecond point. In a retracted position, the distal member may bepivotably connected to the proximal member longitudinally in between thefirst point and the second point. In the retracted position, the distalmember and the proximal member may be disposed within the cannula at theopening and may extend generally along the longitudinal direction. Fromthe retracted position, moving the actuator rod in a distal directionrelative to the cannula may push the proximal member and the distalmember such that the proximal member pivots with respect to the actuatorrod and the distal member, the distal member pivots with respect to theproximal member and the first point, and the proximal member and thedistal member move laterally out of the opening.

In another aspect, the actuator rod may be connected to the proximalmember by a longitudinally adjustable connection, and rotation of theactuator rod may adjust the distance between the actuator handle and theproximal member.

In another aspect, the device may include a locking mechanism that, inan extended position of the distal member and the proximal member,prevents movement of the actuator rod in the longitudinal direction butallows rotational movement of the actuator rod.

Another aspect provides a method for preparing a surgical site. Themethod includes inserting into the surgical site a device in a retractedposition. The device may have a retractable tool and an actuatorconnected to the retractable tool. The retractable tool may include adistal member and a proximal member. A distal side of the distal membermay be fixed in a longitudinal direction and pivotable at a point ofrotation. A proximal side of the proximal member may be pivotablyconnected to the actuator. In the retracted position, the distal membermay be pivotably connected to the proximal member longitudinally inbetween the point of rotation and the proximal side of the proximalmember. In the retracted position, the distal member and the proximalmember may extend generally along the longitudinal direction. The methodmay further include moving the actuator in a distal direction so thatthe actuator pushes the proximal member and the distal member such thatthe proximal member pivots with respect to the actuator and the distalmember, the distal member pivots with respect to the proximal member andthe point of rotation, and the proximal member and the distal membermove laterally outward with respect to the longitudinal direction andacross the surgical site.

In another aspect, the method further includes sizing the surgical siteusing the extended proximal member and the extended distal member.

In another aspect, the method further includes cutting the surgical siteusing the extended proximal member and the extended distal member.

In another aspect, the method further includes distracting the surgicalsite using the extended proximal member and the extended distal member.

In another aspect, the method further includes locking the actuator toprevent longitudinal movement of the actuator when the proximal memberand the distal member are in a fully extended position, and moving thedevice such that the fully extended proximal member and the fullyextended distal member move within the surgical site.

In another aspect, the method further includes moving the actuator in aproximal direction so that the actuator pulls the proximal member andthe distal member such that the proximal member pivots with respect tothe actuator and the distal member, the distal member pivots withrespect to the proximal member and the point of rotation, and theproximal member and the distal member move laterally inward with respectto the longitudinal direction to the retracted position.

Other systems, methods, features, and advantages of the presentembodiments will be, or will become, apparent to one with skill in theart upon examination of the following figures and detailed description.It is intended that all such additional systems, methods, features, andadvantages be included within this description, be within the scope ofthe present embodiments, and be protected by the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present embodiments can be better understood with reference to thefollowing drawings and description. The components in the figures arenot necessarily to scale, emphasis instead being placed uponillustrating the principles of the present embodiments. Moreover, in thefigures, like reference numerals designate corresponding partsthroughout the different views.

FIG. 1.1 is a schematic diagram of a perspective view of an embodimentof a device for preparation of surgical sites, and in particular,vertebral members;

FIG. 1.2 is a schematic diagram of a partial plan view of the handleportion and tip portion of the device of FIG. 1.1;

FIG. 1.3 is a schematic diagram of an end view of the device of FIG. 1.1looking in a longitudinal direction from the tip portion toward thehandle portion;

FIG. 1.4 is a schematic diagram of a cross-sectional view of the deviceof FIG. 1.1 taken along section A-A of FIG. 1.3;

FIG. 2 is a schematic diagram illustrating the device of FIG. 1.1 in aretracted position, with the actuator handle pulled back and with theretractable A-frame members of the retractable tool retracted;

FIG. 3 is a schematic diagram illustrating the device of FIG. 1.1 in adeployed position, with the actuator handle pushed in and with theretractable members of the retractable tool fully extended;

FIG. 4 is a schematic diagram of an enlarged view of the tip portion ofthe device of FIG. 1.1, with the retractable members fully retracted;

FIG. 5 is a schematic diagram of an enlarged view of the tip portion ofthe device of FIG. 1.1, with the retractable members beginning to extendas the actuator handle is rotated or moved in a distal direction;

FIG. 6 is a schematic diagram of an enlarged view of the tip portion ofthe device of FIG. 1.1, with the retractable members continuing toextend in comparison to FIG. 5, as the actuator handle is furtherrotated or moved in a distal direction;

FIG. 7 is a schematic diagram of an enlarged view of the tip portion ofthe device of FIG. 1.1, with the retractable members fully extended;

FIGS. 8.1-8.3 are schematic diagrams of full and partial cross-sectionalviews of the device of FIG. 1.1;

FIG. 9 is a schematic diagram of a perspective view of internalcomponents of the device of FIG. 1.1;

FIG. 10 is a schematic diagram of a side view of internal components ofthe device of FIG. 1.1;

FIG. 11 is a schematic diagram of a cross-sectional view of the handleportion of the device of FIG. 1.1;

FIG. 12 is a schematic diagram of a cross-sectional view of the tipportion of the device of FIG. 1.1;

FIG. 13 is a schematic diagram of a perspective view of the tip portionof a device for preparation of surgical sites, and in particular,vertebral members, according to an alternative embodiment;

FIGS. 14.1-14.4 are schematic diagrams of an embodiment of a depth gaugeassembly;

FIG. 15.1 is a schematic diagram of a perspective view of anotherembodiment of a retractable tool of a device for preparation of surgicalsites, and in particular, vertebral members, shown in the retractedposition;

FIG. 15.2 is a schematic diagram of a perspective view of theretractable tool of FIG. 15.1, shown at an intermediate position betweenthe retracted position and the fully extended position, as an actuatorhandle attached to the retractable tool is rotated or moved in a distaldirection;

FIG. 15.3 is a schematic diagram of a perspective view of theretractable tool of FIG. 15.1, shown in the fully extended position;

FIG. 16.1 is a schematic diagram of a perspective view of anotherembodiment of a retractable tool of a device for preparation of surgicalsites, and in particular, vertebral members, shown in the retractedposition;

FIG. 16.2 is a schematic diagram of a perspective view of theretractable tool of FIG. 16.1, shown at an intermediate position betweenthe retracted position and the fully extended position, as an actuatorhandle attached to the retractable tool is rotated or moved in a distaldirection;

FIG. 16.3 is a schematic diagram of a perspective view of theretractable tool of FIG. 16.1, shown in the fully extended position;

FIG. 17 is a schematic diagram illustrating an embodiment of a methodfor preparation of surgical sites, and in particular, vertebral members,using the device of FIG. 1.1;

FIGS. 18.1-18.4 are schematic diagrams illustrating an embodiment of amethod for preparation of surgical sites, and in particular, vertebralmembers, using the device of FIG. 15.1;

FIGS. 19.1-19.2 are schematic diagrams illustrating an embodiment of amethod for preparation of surgical sites, and in particular, vertebralmembers, using the device of FIG. 16.1;

FIGS. 20.1-20.3 are schematic diagrams of perspective views of analternative embodiment of a retractable tool of a device for preparationof surgical sites, and in particular, vertebral members, havingspecially shaped or contoured surfaces; and

FIG. 21 is a schematic diagram illustrating an embodiment of a methodfor preparation of surgical sites, and in particular, vertebral members,using the device of FIG. 20.1.

DETAILED DESCRIPTION

Embodiments provide devices and methods for preparing surgical sites,and in particular, for preparing vertebral members for receiving animplant.

Based on experience with implanting spinal fusion implants (e.g., spinalfusion implants made of coiled metal strips) in cadaver laboratorytests, the inventors found that disc nucleus preparation completedthrough a small incision opening in the annulus, i.e., small annulotomy(smaller than a coiled spinal fusion coil implant), may take a longertime than in an open procedure. A challenging aspect of the non-openprocedures, such as minimally invasive spine surgeries or percutaneousprocedures, is that a doctor may not be able to see how an instrument isaffecting the area, e.g., when scraping. This area is preferably clearedof nucleus tissue and also cartilage on the vertebral endplates so thatthe vertebral endplate bone is exposed. The intervertebral space (alsoreferred to herein as a void, void space, or disc space) is preferablygeometrically precise in all directions to provide a good fit for aspinal fusion implant. If tissue or bone intrudes into the requireddiscectomy void space, deployment of a spinal fusion implant may beinhibited. If excessive scraping occurs on the vertebral endplates, thesofter cancellous bone may be exposed and compromise the structuralbearing surface for the implant. Effective discectomy and endplatepreparation helps ensure successful deployment and fusion of a spinalfusion implant, e.g., a spinal fusion coil. Examples of spinal fusioncoils are disclosed in U.S. Pat. No. 7,922,767 to Sack et al., issuedApr. 12, 2011, and U.S. Pat. No. 8,197,548 to Sack et al., issued Jun.12, 2012, both of which are herein incorporated by reference in theirentirety. To view and prepare an intervertebral space, conventionalmethods have used large openings in the disc and have pounded, orotherwise forced, spinal fusion implants into place.

For consistency and convenience, directional adjectives are employedthroughout this detailed description corresponding to the illustratedembodiments. The term “longitudinal,” as used throughout this detaileddescription and in the claims, refers to a direction extending a lengthof a component. The term “longitudinal axis,” as used throughout thisdetailed description and in the claims, refers to an axis oriented in alongitudinal direction. The term “lateral direction,” as used throughoutthis detailed description and in the claims, refers to a side-to-sidedirection extending a width of a component. The term “lateral axis,” asused throughout this detailed description and in the claims, refers toan axis oriented in a lateral direction. The term “horizontal,” as usedthroughout this detailed description and in the claims, refers to anydirection substantially parallel with the longitudinal direction, thelateral direction, and all directions in between. The term “vertical,”as used throughout this detailed description and in the claims, refersto a direction generally perpendicular to both the lateral andlongitudinal directions, along a vertical axis.

Embodiments provide an instrument that may rapidly check a discectomyvoid space, and may include further provisions for clearing a preciselysized and shaped void, free of imperfections such as divots andprotrusions. In one embodiment, an instrument provides retractablemembers, such as A-frame members, that may move from a flatconfiguration for insertion through a small opening, to a raisedconfiguration for checking the dimensions of an intervertebral space. Aninstrument may also include provisions for scraping vertebral bodies,such as rasp teeth, sharp edges, or other cutting structures on theretractable members and/or cannula tip.

FIGS. 1.1-1.4 illustrate an embodiment of a device 100 for preparationof surgical sites, and in particular, vertebral members. As shown,device 100 may include a tip portion 19 on a distal side of the device100 and a handle portion 20 on a proximal side of the device 100. (Asused herein, proximal and distal refer to positions relative to aposition of a user of the device, such as a surgeon holding and usingthe device.) A cannula 1 may extend from the tip portion 19 to thehandle portion 20. A fixed handle 3 may be affixed to the cannula 1 atthe handle portion 20. The fixed handle 3 may be affixed to the cannula1 using lock pins 12. A depth gauge assembly 13 may be affixed to anouter surface of the cannula 1, extending between the tip portion 19 andthe handle portion 20. An actuator assembly may be disposed insidecannula 1, and may include an actuator handle 14 and an actuator rod 6,as shown in FIG. 2. The actuator assembly may be used to adjust thefully deployed height of a retractable tool 21 and to deploy and retracttool 21. The actuator rod 6 may be connected to the actuator handle 14using a locking pin 11. As shown, the actuator handle 14 and fixedhandle 3 may be T-shaped. A cannula, such as cannula 1, may have agenerally constant cross-sectional size and shape from the tip portionto the handle portion, or may vary in cross-sectional size and shape,for example, depending on the particular surgical site for which adevice is intended.

Tool 21 may include a slide connector 4 and A-frame members, including adistal member 2 and a proximal member 5. A proximal side of slideconnector 4 may be connected to a distal side of the actuator rod 6,while a distal side of the slide connector 4 may be pivotably connectedto a proximal side of the A-frame member 5 by a pivot pin 9A. A distalside of the A-frame member 5 may be pivotably connected to a proximalside of the A-frame member 2 by a pivot pin 9B. A distal side of theA-frame member 2 may be connected to the cannula 1 by a pivot pin 8. Thepivotable connections associated with the tool 21 may allow the tool 21to extend from, and retract into, an opening in the cannula 1 at the tipportion 19 of the device 100, as the slide connector 4 is moved distallyand proximally by the actuator rod 6 of the actuator assembly.

A surgical site preparation device may include provisions for lockingthe position of a tool. As shown in FIGS. 1.1-1.4, for example, device100 may include a lock mechanism, including a spring 10 and button 7having locking structures that cooperate with locking structures on theactuator rod 6. The locking structures may be, for example, ribs and/orgrooves that engage each other. The spring 10 and button 7 may be biasedto engage the locking structures when the button 7 is in an extended,unpressed position, and to release the locking structures when thebutton 7 is pressed. As shown, the locking mechanism of device 100 maybe disposed inside the fixed handle 3.

A surgical site preparation device may include provisions for adjustingthe configuration of the device before use. As shown best in FIGS. 1.4,8.1, 8.2, and 12, slide connector 4 may be adjustably connected to theactuator rod 6, for example, by a threaded connection that allowslengthwise adjustments along the longitudinal direction of the device100. With this adjustable connection, the actuator handle 14 may berotated to adjust and preset the fully deployed height of the pivotingA-frame members 2 and 5 of tool 21. As shown in the cross-sectionalviews of FIGS. 8.1 and 8.2, the actuator handle 14 may be rotated toadvance or retract the threads of the distal end of the actuator rod 6into or out of the threads of the slide connector 4, thereby adjustingthe distance between the actuator handle 14 and the proximal A-framemember 5. In the depicted embodiment, the actuator rod 6 has a malethreaded end that is received by a female threaded end of the slideconnector 4, though the reverse threaded connection would suffice aswell. In addition, other adjustable connections could be used. In theillustrated embodiment, by rotating the actuator handle 14, a user maypreset the fully deployed height of the tool 21, for example, to size orexpand an intervertebral space. This may be done while the device 100 isnested in a graduated feature of a sterilization tray in order toachieve the desired extension to match the implant.

To allow for the configuration adjustments, a lock mechanism of asurgical site preparation device may include provisions that permitrotation but limit or prevent axial movement. As shown in FIGS. 8.3 and11, for example, lock button 7 may be spring loaded (by spring 10)outwardly to engage radial ribs and grooves 26 of button 7 with radialribs and grooves 27 of actuator rod 6. An example of that type ofengagement is shown at location 24 in FIGS. 8.3. The ribs and groovesmay therefore permit rotational movement but not axial movement. Asrepresented by the arrow 25 in FIG. 8.3, pressing the button 7disengages the ribs and grooves.

After a configuration adjustment is made, the lock release button 7 maybe depressed to allow the actuator handle 14 to be pulled back tocollapse the A-frame members 2 and 5 of tool 21 for convenient insertioninto a disc opening, as shown in FIG. 2, for example. The tip portion 19of device 100 may be inserted to the correct depth into the disc spacethrough an annulotomy and rotated 90 degrees. Then, the actuator handle14 may be pushed inward until the actuator handle 14 clicks and locksinto place, when one or more annular ribs and/or grooves of a springloaded button 7 engage corresponding annular ribs and/or grooves ofactuator rod 6. This action extends the A-frame members 2 and 5 to thepreset fully deployed height, as shown in FIG. 3, for example. A usermay then repeatedly push forward and pull back on the entire device (forexample, holding the handle portion 20 of the device 100) to verify thesize of a discectomy void space, or to cut bone or tissue.

FIG. 11 illustrates an enlarged perspective view of an exemplaryoperation of a locking mechanism and actuator rod according to anembodiment. As shown, when lock button 7 is pressed against the force ofthe spring 10, the radial ribs and grooves 26 may disengage from theradial ribs and grooves 27 on the actuator rod 6. This disengagementallows the actuator rod 6 and the connected actuator handle 14, alongwith the slide connector 4 (not shown in FIG. 11), to freely move in anaxial direction within travel limits. The outward limit may bedetermined by the full retraction of the A-frame members 2 and 5 intothe opening 28 of the cannula 1. Inward travel may be limited by adistal side of the actuator handle 14 contacting a proximal side of thefixed handle 3. This travel distance may be determined by the number ofturns applied to the actuator handle 14.

FIGS. 4-7, 10, and 12 illustrate further details of the structure andoperation of a retractable tool of a surgical site preparation device,according to embodiments. FIG. 4 illustrates tool 21 in a fullyretracted position, with A-frame members 2 and 5 stowed in the opening28 of cannula 1. FIG. 5 illustrates tool 21 in an intermediate positionas the A-frame members 2 and 5 are extending out of the opening 28 ofthe cannula 1, as a result of either the rotation of the actuator handle14 during a presetting period of adjustment or the axial movement of theactuator handle 14 in the distal direction during use. FIG. 6illustrates tool 21 in a further intermediate position continuing towardits fully deployed position. FIG. 7 illustrates tool 21 in its fullydeployed position, with A-frame members 2 and 5 at the fully extendedheight to which they were preset. FIG. 7 also shows a blank hole 29 inthe cannula 1, which may be used to insert pivot pin 9A into the A-framemember 5 and slide connector 4 during assembly of the device 100.

For clarity purposes, FIGS. 9 and 10 illustrate the tool 21 and slideconnector 4, without other portions of device 100, according to anembodiment. As shown, the pivotable connections between the tool 21,slide connector 4, and cannula 1 (not shown) allow the A-frame members 2and 5 to pivot with respect to the slide connector 4, the cannula 1, andeach other, to raise and lower for deployment and retraction,respectively. As represented by arrow 30 in FIG. 9, deployment may beaccomplished by moving slide connector 4 in a distal direction to raiseA-frame members 2 and 5. Subsequently, as represented by arrow 31 inFIG. 9, retraction may be accomplished by moving slide connector 4 backin a proximal direction to lower A-frame members 2 and 5.

As shown in FIG. 10, in an embodiment, pivot pin 9B may be configured toremain above a thrust center line 32 between pivot pin 8, which is fixedto the cannula 1, and pivot pin 9A, which moves as slide connector 4moves (as represented by arrow 39). This offset position of pivot pin 9Babove thrust center line 32 may ensure that the A-frame members 2 and 5extend (as represented by arrow 33) and fully retract when actuated bythe slide connector 4.

Embodiments may include provisions for securely limiting the travel oftool 21 when reaching the fully deployed position. As an example, thecross-sectional perspective view of FIG. 12 illustrates the travel oftool 21 limited by surface contact between an internal flat surface 34of the cannula 1 and a corresponding flat surface 35 of the A-framemember 2. In adjusting the full deployment height of the tool 21 (as theactuator rod 6 and slide connector 4 rotate with respect to each other),a user may feel the contact between surfaces 34 and 35 as the actuatorhandle 14 is rotated while the ribs and grooves 27 of the actuator rod 6are engaged with the ribs and grooves 26 of the button 7 (see, e.g.,FIG. 11). This feel of contacting surfaces 34 and 35 may signal to theuser that the tool 21 has reached its upper limit of travel anddeployment height adjustment.

Embodiments may include provisions for limiting the insertion depth ofthe tip portion of the device 100. For example, as shown in FIGS. 1.4and 14.1-14.4 an adjustable depth gauge assembly 13 may limit theinstrument insertion depth into an annulotomy and may be aligned withnumerical graduations that correspond to graduations on a correspondingdeployment instrument used to deploy a spinal implant. This may allowquick and accurate depth control of the deployment instrument inreference to the newly cleared void so that a spinal implant is properlydeployed, e.g., allowing a spinal fusion coil to automatically deploy inthe correct location.

As shown in FIGS. 1.4, 2, 3, and 14.1-14.4, an embodiment of a depthgauge assembly 13 may include a depth gauge 15, a depth gauge lock 16, afastener 17, a spring 18, and a mounting plate 22 and support 23attached to the cannula 1. For purposes of illustration, FIGS. 2 and 3depict the mounting plate 22 and support 23, without the remainingcomponents of the depth gauge assembly 13. As shown in FIGS. 2 and 3,mounting plate 22 may include incremental ridges and openings 42 withwhich the depth gauge lock 16 may engage. For example, a U-shapedconfiguration of depth gauge lock 16, as shown in FIG. 14.4, may engagethe complementary shape of the ridges and openings 42 of the mountingplate 22. The spring-mounted fastener 17 allows the depth gauge lock 16to engage and disengage the mounting plate 22, to allow the depth gauge15 to slide longitudinally along the mounting plate 22 and support 23 toa desired position at which point the depth gauge lock 16 may lock thedepth gauge 15.

Some embodiments may include provisions for preparing surfaces of asurgical site, such as preparing surfaces of vertebral members forimplantation. In embodiments, device 100 may have sharpened edges orfile teeth on the A-frame members 2 and 5 and file teeth on the narrowedges of the tip portion of the cannula 1. Those provisions may allow adevice 100 to be used as a rasp or scraper instrument to facilitate thecleanout of a disc space, and may facilitate the creation of a cleartrapezoidal void space with a precise gap having parallel surfacesbetween vertebral endplates.

In one embodiment, FIG. 13 illustrates A-frame members 2 and 5 havingstraight scraping edges 36 and a tip portion of cannula 1 having raspteeth 37 on the narrow edge of the cannula 1.

In embodiments, file teeth may be added to the narrow edges of device100 to facilitate limited bone removal at the rim of a vertebralendplate. This ensures that the endplates remain parallel even thoughthe device may be primarily distracting the opening from one side. Inaddition, the filed groove may ensure that an instrument deploying aspinal implant registers in the exact location at the posterior edge ofthe disc opening. Additionally, as shown in FIG. 4, for example, largeopenings 38 in the A-frame members 2 and 5 may allow disc tissue to exitfrom within the A-frame members, to avoid jamming the A-frame membersand preventing full retraction of the A-frame members 2 and 5 to a flatposition. A cleanout port (e.g., port 97 in FIG. 1.4) may allow forflushing of the device 100 prior to sterilization for reuse.

In embodiments used for sizing, a surgeon may start with a smallerdevice 100 (width of the device or height of the disc space) to checkthe discectomy void. If the fit is loose, the surgeon may move up to thenext size. The fully deployed height of the A-frame members 2 and 5 maybe incrementally increased to size the discectomy void and/or to adjustthe reach of any rasp or scraper features provided on the device. Theremay also be various sizes of the A-frame. In embodiments, the fullydeployed height of the retractable members may correspond in size to thespinal implant to be implanted and the deployment instrument to be usedto implant the spinal implant, so that the void is correctly sized.

In embodiments, device 100 may be rapidly removed by depressing the lockbutton 7 and pulling back on the actuator handle 14. The pitch of thethreads on the rod may be changed to adjust the effect of the turns ofthe actuator handle 14.

In embodiments, device 100 may also be used as a distraction instrument.For example, device 100 may be inserted into a disc space through anannulotomy with the A-frame members facing a first vertebra endplate,and instead of then rotating the instrument 90 degrees for sizing orrasping purposes, the device 100 would remain oriented with the A-framemembers facing the first vertebra endplate and the opposite side of thetip portion of the device 100 facing a second vertebra endplate. Thedevice 100 would then be actuated to raise the A-frame members 2 and 5,which would then push the first vertebra endplate as the opposite sideof the tip portion of the device 100 pushes the second vertebraendplate. As the A-frame members 2 and 5 rise, the device 100 wouldcause distraction in the disc space.

In embodiments, one or both of the A-frame members 2 and 5 may have acontact surface at their adjoining ends so that during distraction themembers provide more distributed contact with a vertebra endplate,rather than contact by a corner of the members. For example, referringto FIGS. 5-7, the proximal end 71 of member 2 may have a rounded orflattened contour, rather than the corner edge shown in those figures.Such a contoured contact surface may provide better contact with avertebra endplate and may allow sliding of a member against the vertebraendplate with less resistance.

In embodiments, device 100 may be used in vertebral bodies in a mannersimilar to that described above to achieve the same results except forthe intervertebral space.

In embodiments, device 100 may have different configurations dependingon the desired functions. For example, device 100 may have smooth edgeson the A-frame members 2 and 5 to check the size and clearance of adiscectomy void. As another example, device 100 may have sharpened edgesor file teeth on the A-frame members 2 and 5 and file teeth on thenarrow edges of the body of the instrument to use the device as a raspor scraper to facilitate the cleanout of a disc space. As anotherexample, the A-frame members 2 and 5 may have curved cutting edges tobetter match the shape of an annulus, such as an oval shape, and topermit the clearing of tissue as close to the edge of the annulus aspossible. An embodiment of curved edges is shown and described below inreference to FIGS. 20.1-20.3. As another example, device 100 may have acannula with a rasp surface or a smooth surface and A-frame members witha rasp surface or a smooth surface.

Embodiments of a device for preparation of surgical sites (e.g.,preparation of vertebral members) may include provisions foraccommodating varying anatomies or other structural conditions in whicha device is used, which may depend on the particular surgical site of apatient. Examples of such variations may include the size and shape ofan annulotomy through which a device is inserted and the size and shapeof an intervertebral space in which a device is used. Embodiments maytherefore provide varying configurations of extending and retractingmembers of a tool. As shown in FIGS. 4-7 for example, an embodiment of atool may provide A-frame members 2 and 5 of a tool 21, which are eachattached at their ends to each other at pivot pin 9B. Other embodimentsmay link the extending and retracting members of a tool in differentconfigurations, e.g., suitable for different structural conditions oroperational objectives, such as sizing or rasping. For example, insteadof attaching the extending and retracting members at their ends, otherembodiments may attach a first member to an intermediate portion of asecond member, so that a portion of the second member extends beyond theattachment point.

As shown in FIGS. 15.1-15.3, an alternative embodiment provides a device200 for preparation of surgical sites, and in particular, vertebralmembers, having a tool 221 with a distal member 202 and a proximalmember 205. A proximal side of slide connector 4 may be connected to adistal side of an actuator rod, while a distal side of the slideconnector 4 may be pivotably connected to a proximal side of theproximal member 205 by a pivot pin. A distal side of the proximal member205 may be pivotably connected to an intermediate portion of distalmember 202 by a pivot pin 9B. A distal side of distal member 202 may beconnected to the cannula 1 by a pivot pin 8. The pivotable connectionsassociated with the tool 221 may allow the tool 221 to extend from, andretract into, an opening 28 in the cannula 1 at the tip portion 19 ofthe device 200, as the slide connector 4 is moved distally andproximally by the actuator rod of the actuator assembly.

As shown in FIGS. 15.2 and 15.3, attaching proximal member 205 to anintermediate portion of distal member 202 may provide an extendingportion 299 of distal member 202. The attachment point at pivot pin 9Bmay be positioned at any intermediate location as appropriate for aparticular application. In the embodiment of FIGS. 15.1-15.3, theintermediate location is approximately at a midpoint of the distalmember 202. Other intermediate locations are possible, however, and maydepend on factors such as the desired length of the extending portion299 and the ability to pivot the distal member 202 outward as theproximal member 205 is forced distally in the longitudinal direction,thereby pushing the distal member 202 at the pivot pin 9B to move thedistal member 202 outward.

Providing an extending portion may allow a slim profile for a tool inthe fully deployed condition. The slim profile may allow a user toconveniently maneuver a device within a surgical site, and may provideenhanced control and feel when measuring the size of the disc space orwhen removing bone or tissue with the device. For example, as shown inFIG. 15.3, once the device 200 is deployed within an implantation site,the cannula 1 can be moved back and forth in the longitudinal direction,as well as pivoted about the tip of the cannula 1, to move the distalmember 202 within the implantation site, and to move the extendingportion 299 both longitudinally and pivotally. Distal member 202 mayinclude cutting edges 236 that may be used to cut bone or tissue as thedevice 200 is moved. Proximal member 205 may also include cutting edges236.

Since the extending portion 299 causes the distal member 202 and theproximal member 205 to overlap in the retracted position, embodimentsmay include provisions for allowing the members 202 and 205 to lie flushwith each other and with the outer surface of the cannula 1. An exampleof a retracted, flush configuration is shown in FIG. 15.1. To allow sucha configuration, as shown in FIG. 15.2, an embodiment provides arecessed portion 297 of proximal member 205 that receives an end portion295 of distal member 202. Likewise, distal member 202 may include arecessed portion 293 that receives an end portion 291 of proximal member205. As shown in FIG. 15.1, in the retracted position, the recessedportions 293 and 297 allow the proximal member 205 and the distal member202 to overlap each other, nest within each other, and assume agenerally straight, longitudinal configuration, with the outer surface289 of the proximal member 205, the outer surface 287 of the distalmember 202, and the outer surface 285 of the cannula 1 generally flushwith each other. That flush configuration may allow convenient insertioninto a small incision or annulotomy, and may avoid catching on ordamaging surrounding tissue.

Another embodiment for accommodating varying structural conditions of asite may provide an extending portion on a proximal member of aretractable tool. As shown in FIGS. 16.1-16.3, an embodiment provides adevice 300 for preparation of surgical sites, and in particular,vertebral members, having a retractable tool 321 with a distal member302 and a proximal member 305. A proximal side of slide connector 4 maybe connected to a distal side of an actuator rod, while a distal side ofthe slide connector 4 may be pivotably connected to a proximal side ofthe proximal member 305 by a pivot pin. An intermediate portion of theproximal member 305 may be pivotably connected to a proximal side ofdistal member 302 by a pivot pin 9B. A distal side of distal member 302may be connected to the cannula 1 by a pivot pin 8. The pivotableconnections associated with the tool 321 may allow the tool 321 toextend from, and retract into, an opening 28 in the cannula 1 at the tipportion 19 of the device 300, as the slide connector 4 is moved distallyand proximally by the actuator rod of the actuator assembly.

As shown in FIGS. 16.2 and 16.3, attaching distal member 302 to anintermediate portion of proximal member 305 may provide an extendingportion 399 of proximal member 305. The attachment point at pivot pin 9Bmay be positioned at any intermediate location as appropriate for aparticular application. In the embodiment of FIGS. 16.1-16.3, theintermediate location is approximately at a midpoint of the proximalmember 305. Other intermediate locations are possible, however, and maydepend on factors such as the desired length of the extending portion399 and the ability to pivot the proximal member 305 outward as theproximal member 305 is forced distally in the longitudinal direction,thereby pushing the distal member 302 at the pivot pin 9B to move thedistal member 302 and the proximal member 305 outward.

As with the previous embodiment, providing an extending portion mayallow a slim profile for a tool in the fully deployed condition. Theslim profile may allow a user to conveniently maneuver a device within asurgical site, and may provide enhanced control and feel when measuringthe size of the disc space or when removing bone or tissue with thedevice. For example, as shown in FIG. 16.3, once the device 300 isdeployed within an implantation site, the cannula 1 can be moved backand forth in the longitudinal direction, as well as pivoted about thetip of the cannula 1, to move the distal member 302 within theimplantation site, and to move the extending portion 399 bothlongitudinally and pivotally. Proximal member 305 may include cuttingedges 336 that may be used to cut bone or tissue as the device 300 ismoved. Distal member 302 may also include cutting edges.

Since the extending portion 399 causes the proximal member 305 and thedistal member 302 to overlap in the retracted position, embodiments mayinclude provisions for allowing the members 302 and 305 to lie flushwith, or below, the outer surface of the cannula 1. An example of aretracted, flush configuration is shown in FIG. 16.1. To allow such aconfiguration, as shown in FIG. 16.2, an embodiment provides a recessedportion 397 of proximal member 305 that receives an end portion 395 ofdistal member 302. Likewise, distal member 302 may include a recessedportion 393 that receives an end portion 391 of proximal member 305. Asshown in FIG. 16.1, in the retracted position, the recessed portions 393and 397 allow the proximal member 305 and the distal member 302 tooverlap each other, nest within each other, and assume a generallystraight, longitudinal configuration, with the outer surface 389 of theproximal member 305 generally flush with the outer surface 385 of thecannula 1, and with the outer surface 387 of the distal member 302recessed below the outer surface 385 of the cannula 1 and the outersurface 389 of the proximal member 305. That flush and recessedconfiguration may allow convenient insertion into a small incision orannulotomy, and may avoid catching on or damaging surrounding tissue.

Another embodiment for accommodating varying structural conditions of asurgical site may provide a specially shaped or contoured retractablemember of a tool, to match the shape of a surgical site (e.g., anannulus) in which a device is inserted. Matching the shape may allow theretractable member to be positioned closer to, or even in substantiallyfull contact with, a perimeter wall of the surgical site. The matchingcontours may allow the tool to provide a more accurate measurement ofthe surgical site and a more complete reach to cut or otherwise clearbone or tissue from the site. As an example, a specially shaped edgeand/or outer surface of a retractable member may be curved to match aportion of an oval-shaped annulus. Other shapes and contours, such astriangular or other polygonal shapes, are possible, depending on theshapes of the anatomical structures for which the tool is intended.

As an example, as shown in FIGS. 20.1-20.3, an embodiment may provide adevice 400 for preparation of surgical sites, and in particular,vertebral members, having a tool 421 with a distal member 402 and aproximal member 405. Device 400 and tool 421 may be similar in manyrespects to device 200 and tool 221 of the embodiment of FIGS.15.1-15.3, for example, in terms of the configurations and attachmentsof the retractable members of the tools. Those similarities would beapparent to the skilled artisan from the figures and description, andfor conciseness, will not be described herein. Device 400 differs fromdevice 200 in aspects related to the shapes of the edges and outersurfaces of the retractable members. In particular, as shown in FIGS.20.1-20.3, distal member 402 may have curved lateral edges 436 and acurved outer surface 437, which may correspond to the curve of aperimeter wall of a surgical site, such as a curved perimeter wall of anannulus. As shown in the fully deployed position of FIG. 20.3, thecomplementary shapes between the tool 421 and a perimeter wall of asurgical site may allow the outer surface 437 to be positioned near, orin substantial contact with, the wall, so that the tool 421 mayaccurately measure the size of the site or may clear tissue or bone fromthe site starting close to the wall and using the curved lateral edges436 for cutting.

As an example, referring to FIG. 21, in sizing or clearing a surgical orimplantation site, device 400 may be inserted into an annulotomy 540 ofan annulus 503 and actuated to the fully deployed position of FIG. 20.3,after which the entire device 400 may be moved longitudinally (generallyleft and right in FIG. 21) or may be moved pivotally around the tip ofthe cannula 1, within the disc space 504 of the annulus 503.Alternatively, the cannula 1 may be maintained at a substantially fixedposition, and the tool 421 may be extended and retracted moving back andforth between the fully retracted position of FIG. 20.1 and the fullyextended position of FIG. 20.3. As the tool 421 moves between those endpositions, distal member 402 may confirm a clear opening within the site(e.g., the disc space 504 in FIG. 21) equal to the volume in which thedistal member 402 pivots and, in addition, may clear tissue and bonefrom the site as the distal member 402 moves within the site and thelateral edges 436 scrape the tissue and bone.

In further embodiments, specially shaped edges and/or outer surfaces maybe provided on the proximal member 305 of the device 300 of FIGS.16.1-16.3 and on one or both of the proximal member 5 and distal member2 of the device 100 of FIGS. 1.1-1.4.

Embodiments provide methods for the preparation of surgical sites, andin particular, vertebral members, using the devices disclosed herein. Inan embodiment, a tip portion of a surgical site preparation device isinserted through an annulotomy until at least a portion of theretractable tool of the device is within the annulus. Optionally, ifnecessary, the device may be rotated after insertion to face theretractable tool in a desired extension direction. For example, forsizing or clearing an annulus, the device may be rotated such that theretractable tool faces in a horizontal direction between the vertebralendplates. In another example, for distracting, the device may berotated such that the retractable tool faces in a vertical directionfacing a vertebral endplate. The device may also be rotated to thedesired orientation and then inserted into the annulotomy.

After the retractable tool is facing the desired extension direction,the retractable tool is then actuated so that the retractable members ofthe retractable tool extend laterally away from the tip portion of thedevice, from an initial retracted position to a fully extended position.That movement of the retractable members may be used to indicateclearance within disc space of the annulus and to indicate the size andshape of the disc space. That movement may also be used to clear boneand tissue from the disc space to provide a desired clearance, size, orshape of the disc space. Alternatively, or in addition, once theretractable tool is in the fully extended position, the entire devicemay be moved to move the retractable members of the retractable toolwithin the annulus, to size the disc space within the annulus or toclear bone or tissue from within the annulus. The device may be movedlongitudinally back and forth, may be pivoted about the tip portion ofthe device, or may be moved in combinations of movement thereof.

FIGS. 17-19.2 and 21 illustrate embodiments of methods for thepreparation of surgical sites, and in particular, vertebral members,using the devices disclosed herein. FIG. 21 is described above. FIG. 17illustrates an embodiment of the device 100 of FIG. 1.1 inserted throughan annulotomy 525 and into an annulus 500, with the retractable tool 21in a partially extended position, in between the fully retracted and thefully extended positions. As shown, the device 100 may contact the innerperimeter walls 505 of the annulus 500 to provide indications of thesize and shape of the disc space 506 of the annulus 500. As an example,if the retractable tool 21 contacts a wall 505 of the annulus 500 suchthat further deployment of the tool 21 is hindered or prevented, then auser may determine that the disc space 506 is not sufficiently large(cleared) to receive an implant of a certain size corresponding to thefully deployed tool 21. A user may then use the device 100 to increasethe size of the annulus 500, by using rasp teeth (not shown) on thecannula 1 of the device 100 and/or scraping edges 36 of the tool 21.

FIGS. 18.1-18.4 illustrate an embodiment of the device 200 of FIG. 15.1being deployed in an annulus 501. As shown in FIG. 18.1, the tip portionof device 200 is first inserted through an annulotomy 526 and into anannulus 501. The tip portion of the device 200 may be positioned at alongitudinal end of the annulus 501 with the extension direction of theretractable tool 221 generally facing the interior of the annulus in adirection parallel to the faces of the opposing vertebral endplates.Optionally, the device 200 first could be inserted through theannulotomy 526 with the extension direction of the retractable tool 221generally facing in a direction perpendicular to the faces of theopposing vertebral endplates, and once inserted, may be rotatedapproximately 90 degrees to the position shown in FIG. 18.1.

With at least a portion of the retractable tool 221 inside the discspace 507 of the annulus 501, the retractable tool 221 may then beactuated so that the proximal member 205 and distal member 202 extendout of the opening 28 in the cannula 1, as shown in the partiallyextended position of FIG. 18.2. For clarity and illustration purposes,FIGS. 18.2-18.4 show the annulus 501 in dashed lines. In the embodimentof FIG. 18.2, the proximal member 205 is sliding through the annulotomy526 and simultaneously extending out of the opening 28, while the distalmember 202 is extending out of the opening 28 and pivoting around pivotpin 8 within the disc space 507 of the annulus 501. During this pivotingmotion, the distal member 202 may be used to cut bone or tissue, usingfor example the cutting edges 236. Pieces of cut bone or tissue may passthrough the opening 293 in distal member 202 to help move the loose boneand tissue toward the annulotomy 526 and out of the annulus 501. Thepivoting motion of distal member 202 may also be used to confirmclearance through the disc space 507 of the annulus 501, for receiving acorrespondingly sized implant.

The retractable tool 221 may be further actuated so that the proximalmember 205 and the distal member 202 reach their fully extendedpositions, as shown in FIG. 18.3. The device 200 may be locked at thispoint to secure the proximal member 205 and the distal member 202 attheir fully extended positions. Then, as described in embodiments above,the entire device 200 may be moved to measure the size and shape of thedisc space 507 of the annulus 501 using the retractable tool 221, and tocut bone and tissue to clear the disc space 507 of the annulus 501 forinsertion of a correspondingly sized implant. As an example, FIG. 18.4illustrates a correspondingly sized implant 527 (shown in dashed linesfor clarity and illustration purposes) positioned within the disc space507 of the annulus 501 and within the pivoting arc of the distal member202. Implant 527 may be a coiled implant as shown. Other types ofimplants are also possible.

After the disc space 507 of the annulus 501 is sized and, if necessary,cut, the retractable tool 221 of the device 200 may be retracted so thatthe proximal member 205 and the distal member 202 return to theirinitial retracted positions, lying flat within the opening 28 as shownin FIG. 18.1. The device 200 may then be withdrawn through theannulotomy 526 and out of the annulus 501. The implant 527 may then beinserted using an implantation device, for example, as disclosed in U.S.Pat. No. 7,922,767 to Sack et al., issued Apr. 12, 2011, and U.S. Pat.No. 8,197,548 to Sack et al., issued Jun. 12, 2012, both of which areherein incorporated by reference in their entirety.

Another embodiment of a method for the preparation of surgical sites,and in particular, vertebral members, is shown in FIGS. 19.1-19.2. FIGS.19.1-19.2 illustrate an embodiment of the device 300 of FIG. 16.1inserted through an annulotomy 528 and into disc space 509 of an annulus502, with the retractable tool 321 in a fully extended position. Inreaching the fully extended position, the proximal member 305 ofretractable tool 321 may slide under an edge of the annulotomy 528 asthe proximal member 305 extends outward from the opening 28. As theproximal member 305 is extending, the device 300 may contact the innerperimeter walls 529 of the annulus 502 to provide indications of thesize and shape of the disc space 509 of the annulus 502. As an example,if the retractable tool 321 contacts a wall 529 of the annulus 502 suchthat further deployment of the tool 321 is hindered or prevented, then auser may determine that the disc space 509 of the annulus 502 is notsufficiently large (cleared) to receive an implant of a certain sizecorresponding to the fully deployed tool 321. A user may then use thedevice 300 to increase the size of the disc space 509 of the annulus502, by using scraping edges 336 of the tool 321. In embodiments, asurgeon may start with a smaller size instrument and work up to largersizes.

Once the retractable tool 321 is in the fully extended position, thedevice 300 may be locked to keep the tool 321 in that position. Asdescribed in embodiments above, the entire device 300 may then be movedto move the retractable tool 321 within the annulus 502, for example, tomeasure the cleared disc space 509 in the annulus 502 or to cut andclear bone and tissue from the disc space 509 within the annulus 502.Proximal member 305 and distal member 302 may define openings, such asopening 394 in FIG. 19.1, to allow cut pieces of bone and tissue to passthrough and around the retractable tool 321 and out of the annulus 502through the annulotomy 528. The retractable tool 321 may be used to sizeand/or cut the disc space 509 within the annulus 502 for insertion of acorrespondingly sized implant. As an example, FIG. 19.2 illustrates acorrespondingly sized implant 537 (shown in dashed lines for clarity andillustration purposes) positioned within the annulus 502. A user maydetermine that the implant 537 will fit within the disc space 509 of theannulus 502 by either pivoting the proximal member 305 through thevolume represented by the dashed implant 537 in FIG. 19.2 or by moving(e.g., pushing and/or pulling) the entire device 300 in a longitudinaldirection (generally right to left in FIG. 19.2) to move the retractabletool 321 from one longitudinal wall 529A of the annulus 502 to theopposite longitudinal wall 529B of the annulus 502. Implant 537 may be acoiled implant as shown. Other types of implants are also possible. Inembodiments, different types of instruments can be used in anycombination with other types of instruments to create and/or size adesired discectomy disc space.

Embodiments of a surgical site preparation device may have severaldifferent uses. For example, device 100 of FIG. 1.1 may be used in adisc space to size a discectomy void/3D void for an implant. As anotherexample, a device 100 may be used in a disc space as a rasp or scraperto help perform a discectomy. As another example, a device 100 may beused as a final discectomy preparation tool to prepare the vertebralbodies to create bone bleeding in preparation for the intervertebralbody fusion device. As another example, a device 100 may be used in adisc space as a distractor and to correct deformity. As another example,a device 100 may be used in a vertebral body to create a void. Asanother example, a device 100 may be used in a vertebral body toincrease the height of the vertebral body. In another example, a device100 may be used in a compression fracture of a vertebra to reduce thefracture including vertebral height restoration.

In embodiments, an instrument for preparing surgical sites, and inparticular, vertebral members, may be sized and configured similarly toan instrument for deploying an implant so that a doctor may becomequickly accustomed to the operation of the preparation instrument. Thesimilar constructions may also allow common parts for ease ofmanufacture and cost reduction.

Although embodiments disclosed herein may have been described in thecontext of vertebral members, one of ordinary skill in the art wouldappreciate that the disclosed devices and methods could be used forother surgical applications including, for example, the distraction ofbones for purposes of orthopedic surgery. Accordingly, notwithstandingthe particular benefits associated with the use of the devices andmethods with vertebral members, the present embodiments should beconsidered broadly applicable to any surgical site that could benefitfrom, for example, sizing, clearing, or distraction.

The foregoing disclosure of the preferred embodiments has been presentedfor purposes of illustration and description. It is not intended to beexhaustive or to limit the present embodiments to the precise formsdisclosed. Many variations and modifications of the embodimentsdescribed herein will be apparent to one of ordinary skill in the art inlight of the above disclosure.

While various embodiments have been described, the description isintended to be exemplary, rather than limiting and it will be apparentto those of ordinary skill in the art that many more embodiments andimplementations are possible. Although many possible combinations offeatures are shown in the accompanying figures and discussed in thisdetailed description, many other combinations of the disclosed featuresare possible. Any feature of any embodiment may be used in combinationwith or substituted for any other feature or element in any otherembodiment unless specifically restricted. Therefore, it will beunderstood that any of the features shown and/or discussed in thepresent disclosure may be implemented together in any suitablecombination. Accordingly, the present embodiments are not to berestricted except in light of the attached claims and their equivalents.Also, various modifications and changes may be made within the scope ofthe attached claims.

Further, in describing representative embodiments, the specification mayhave presented a method and/or process as a particular sequence ofsteps. However, to the extent that the method or process does not relyon the particular order of steps set forth herein, the method or processshould not be limited to the particular sequence of steps described. Asone of ordinary skill in the art would appreciate, other sequences ofsteps may be possible. Therefore, the particular order of the steps setforth in the specification should not be construed as limitations on theclaims. In addition, the claims directed to the method and/or processshould not be limited to the performance of their steps in the orderwritten, and one skilled in the art can readily appreciate that thesequences may be varied and still remain within the spirit and scope ofthe present embodiments.

What is claimed is:
 1. A device for preparing a surgical sitecomprising: a retractable tool; and an actuator connected to theretractable tool, wherein the retractable tool comprises a distal memberand a proximal member, wherein a distal side of the distal member isfixed in a longitudinal direction and pivotable at a point of rotation,wherein a proximal side of the proximal member is pivotably connected tothe actuator, wherein in a retracted position the distal member ispivotably connected to the proximal member longitudinally in between thepoint of rotation and the proximal side of the proximal member, whereinin the retracted position the distal member and the proximal memberextend generally along the longitudinal direction, and wherein, from theretracted position, moving the actuator in a distal direction pushes theproximal member and the distal member such that the proximal memberpivots with respect to the actuator and the distal member, the distalmember pivots with respect to the proximal member and the point ofrotation, and the proximal member and the distal member move laterallyoutward with respect to the longitudinal direction.
 2. The device ofclaim 1, wherein the actuator comprises: an actuator rod; and anactuator handle, wherein a distal end of the actuator rod is connectedto the proximal end of the proximal member, and wherein a proximal endof the actuator rod is connected to the actuator handle.
 3. The deviceof claim 2, wherein the actuator rod is connected to the proximal memberof the retractable tool by a threaded connection, and wherein rotationof the actuator rod adjusts the distance between the actuator handle andthe proximal member.
 4. The device of claim 2, further comprising acannula, wherein the actuator rod is disposed within the cannula,wherein the cannula defines an opening at a tip portion of the device,wherein the proximal member and the distal member are disposed withinthe opening when in the retracted position, wherein the distal end ofthe distal member is pivotably connected to the cannula at a distal endof the opening, and wherein the proximal member and the distal memberextend out of the opening when the actuator rod moves in the distaldirection.
 5. The device of claim 4, wherein in the retracted position,an outer surface of the proximal member, an outer surface of the distalmember, and an outer surface of the cannula around the opening aregenerally flush with each other.
 6. The device of claim 3, furthercomprising a locking mechanism that prevents movement of the actuatorrod in the longitudinal direction but allows rotational movement of theactuator rod.
 7. The device of claim 6, wherein the locking mechanismcomprises: at least one of annular ribs and annular grooves on theactuator rod; and a button having at least one of annular ribs andannular grooves that engage and disengage the at least one of annularribs and annular grooves of the actuator rod.
 8. The device of claim 4,further comprising a fixed handle on a proximal side of the cannula,wherein travel of the actuator handle in a distal direction is limitedby contacting the fixed handle.
 9. The device of claim 4, wherein atleast one of the proximal member, the distal member, and the cannulahave surface structures for modifying a surface of a vertebral member.10. The device of claim 1, further comprising a depth gauge assembly.11. The device of claim 1, wherein the device may be used for sizing,surface preparation, or distraction.
 12. The device of claim 1, whereina proximal end of the distal member is pivotably connected to a distalend of the proximal member.
 13. The device of claim 1, wherein a distalend of the proximal member is pivotably connected to an intermediateportion of the distal member, wherein, in the retracted position, anextension portion of the distal member extends beyond the distal end ofthe proximal member toward the proximal end of the proximal member, andoverlaps the proximal member.
 14. The device of claim 13, wherein theproximal member defines a recessed portion for receiving the extensionportion of the distal member so that an outer surface of the distalmember and an outer surface of the proximal member are substantiallyflush when in the retracted position.
 15. The device of claim 1, whereina proximal end of the distal member is pivotably connected to anintermediate portion of the proximal member, wherein, in the retractedposition, an extension portion of the proximal member extends beyond theproximal end of the distal member toward the distal end of the distalmember, and overlaps the distal member.
 16. The device of claim 13,wherein the distal member defines a recessed portion for receiving theextension portion of the proximal member so that an outer surface of theproximal member and an outer surface of the distal member aresubstantially flush when in the retracted position.
 17. The device ofclaim 1, wherein at least one of the proximal member and the distalmember is shaped to match a shape of an implantation site.
 18. A devicefor preparing a surgical site, the device extending from a proximalhandle portion to a distal tip portion and defining a longitudinal axis,the device comprising: a cannula extending generally along thelongitudinal axis and defining an opening at a distal portion of thecannula; a cannula handle fixed to a proximal portion of the cannula; anactuator rod disposed within the cannula and moveable within the cannulain a longitudinal direction generally along the longitudinal axis; anactuator handle that is attached to a proximal portion of the actuatorrod and that is disposed proximal to the cannula handle; a distalmember; and a proximal member, wherein a distal side of the distalmember is pivotably connected at a first point to a distal portion ofthe cannula, wherein a proximal side of the proximal member is pivotablyconnected to the actuator rod at a second point, wherein in a retractedposition the distal member is pivotably connected to the proximal memberlongitudinally in between the first point and the second point, whereinin the retracted position the distal member and the proximal member aredisposed within the cannula at the opening and extend generally alongthe longitudinal direction, and wherein, from the retracted position,moving the actuator rod in a distal direction relative to the cannulapushes the proximal member and the distal member such that the proximalmember pivots with respect to the actuator rod and the distal member,the distal member pivots with respect to the proximal member and thefirst point, and the proximal member and the distal member movelaterally out of the opening.
 19. The device of claim 18, wherein theactuator rod is connected to the proximal member by a longitudinallyadjustable connection, and wherein rotation of the actuator rod adjuststhe distance between the actuator handle and the proximal member. 20.The device of claim 18, further comprising a locking mechanism that, inan extended position of the distal member and the proximal member,prevents movement of the actuator rod in the longitudinal direction butallows rotational movement of the actuator rod.
 21. A method forpreparing a surgical site, the method comprising: inserting into thesurgical site a device in a retracted position, wherein the device has aretractable tool and an actuator connected to the retractable tool,wherein the retractable tool comprises a distal member and a proximalmember, wherein a distal side of the distal member is fixed in alongitudinal direction and pivotable at a point of rotation, wherein aproximal side of the proximal member is pivotably connected to theactuator, wherein in the retracted position the distal member ispivotably connected to the proximal member longitudinally in between thepoint of rotation and the proximal side of the proximal member, andwherein in the retracted position the distal member and the proximalmember extend generally along the longitudinal direction; and moving theactuator in a distal direction so that the actuator pushes the proximalmember and the distal member such that the proximal member pivots withrespect to the actuator and the distal member, the distal member pivotswith respect to the proximal member and the point of rotation, and theproximal member and the distal member move laterally outward withrespect to the longitudinal direction and across the surgical site. 22.The method of claim 21, further comprising sizing the surgical siteusing the extended proximal member and the extended distal member. 23.The method of claim 21, further comprising cutting the surgical siteusing the extended proximal member and the extended distal member. 24.The method of claim 21, further comprising distracting the surgical siteusing the extended proximal member and the extended distal member. 25.The method of claim 21, locking the actuator to prevent longitudinalmovement of the actuator when the proximal member and the distal memberare in a fully extended position, and moving the device such that thefully extended proximal member and the fully extended distal member movewithin the surgical site.
 26. The method of claim 21, further comprisingmoving the actuator in a proximal direction so that the actuator pullsthe proximal member and the distal member such that the proximal memberpivots with respect to the actuator and the distal member, the distalmember pivots with respect to the proximal member and the point ofrotation, and the proximal member and the distal member move laterallyinward with respect to the longitudinal direction to the retractedposition.